What Is SMS Marketing? How It Works, Costs & Rules

SMS marketing (also called text message marketing) is the practice of sending promotional, transactional, or conversational text messages to customers who have explicitly opted in to hear from your business. "SMS" stands for Short Message Service, the standard behind the 160-character texts that land in the native messaging app on nearly every phone. Because it reaches people directly on a device they keep within arm's reach, SMS is one of the most immediate channels in digital marketing.

Done right, it is permission-based, concise, and timely: a flash-sale alert, a back-in-stock notice, an appointment reminder, or an order update. Two things make it work. First, consent: you can only legally text people who have agreed to receive marketing messages. Second, restraint: an SMS list is small and intimate, so the best programs send fewer, more relevant messages than they would over email. This guide covers how SMS marketing works, the message types, real costs, the rules in the United States, and how to launch a first campaign without getting your numbers blocked.

How does SMS marketing work?

At a technical level, your messages don't travel from your laptop straight to a customer's phone. They pass through an SMS marketing platform, which connects to carrier networks (Verizon, AT&T, T-Mobile and others) through messaging aggregators. The platform handles the sending number, consent records, opt-out keywords, and delivery tracking. Operationally, every program follows the same loop:

1. Get a sending number. This is a 10-digit local number (10DLC), a toll-free number, or a short code (a 5-6 digit number for high volume).
2. Build an opted-in list. Collect phone numbers through a checkout checkbox, a website pop-up, or a keyword ("Text JOIN to 12345").
3. Register your number and brand. U.S. carriers require A2P (application-to-person) registration before they will reliably deliver business texts.
4. Send campaigns and automations. Broadcast a one-off promotion, or trigger automated flows like abandoned-cart or shipping updates.
5. Honor opt-outs and measure. Every message must offer an exit (usually "Reply STOP"), and you track delivery, clicks, conversions, and unsubscribes.

What are the types of SMS marketing messages?

Most programs use three categories of text, and understanding the difference matters because they carry different consent rules and different goals:

• Promotional SMS: sales, discount codes, product launches, event invites, and flash-sale alerts. The goal is revenue, and these texts create urgency. In the U.S., promotional texts require explicit marketing consent.
• Transactional SMS: order confirmations, shipping updates, delivery notices, and appointment reminders. These are customer-service messages tied to an action the person already took. Consumers consistently say they want these the most.
• Conversational SMS: two-way replies where a customer can ask a question, place an order, or get support. This may be handled by a live agent, automated keyword replies, or AI that interprets natural language.

SMS vs MMS vs RCS: what's the difference?

These three acronyms describe how the message is delivered, and each affects cost and creative options:

• SMS (Short Message Service): plain text, capped at 160 characters per segment. Longer messages are split into multiple segments and billed accordingly. Cheapest and most universal.
• MMS (Multimedia Messaging Service): supports images, GIFs, and longer text. Richer, more eye-catching, but costs more per send.
• RCS (Rich Communication Services): the modern upgrade to SMS with branded sender names, verification badges, carousels, and read receipts. Adoption is growing across Android and iPhone, but availability still depends on the carrier and device, so SMS remains the dependable baseline.

What are the benefits of SMS marketing?

SMS earns its place because it does a few things no other channel does as well. Industry providers consistently report open rates near 98% and read times within minutes, far above typical email open rates. Treat specific stats directionally, but the pattern is reliable across sources:

• Immediacy: texts are usually read within minutes, which makes SMS ideal for time-sensitive offers, low-stock alerts, and reminders.
• High engagement: because lists are opt-in and small, the people on them genuinely want to hear from you, so click and conversion rates tend to outperform crowded channels.
• Direct and personal: messages land in the same inbox people use for friends and family, with no algorithm deciding who sees them.
• Owned audience: like email, you control the list. Privacy changes such as third-party cookie loss don't break a channel built on first-party consent.
• Cost-efficient at scale: per-message costs are low, and when paired with the high response rate, ROI is strong for the right use cases.

How much does SMS marketing cost?

There is no single price, but costs break into a few predictable buckets. Per-message rates in the U.S. typically run between roughly $0.01 and $0.05 per SMS, according to provider pricing guides such as TextUs, with MMS costing more per send. On top of per-message costs you should budget for:

• Platform fees: a monthly subscription or a pool of message credits, depending on the provider.
• Number and registration fees: securing a 10DLC or toll-free number, plus one-time A2P brand and campaign registration fees charged by The Campaign Registry and carriers.
• MMS premium: image messages cost more than plain SMS, so factor that in if visuals are central to your strategy.
• Carrier and segment math: a message over 160 characters counts as multiple segments and is billed per segment, so concise copy is also cheaper copy.

Is SMS marketing legal? TCPA and 10DLC explained

Yes, SMS marketing is legal in the United States, but only with proper consent and compliance. The governing rules are the Telephone Consumer Protection Act (TCPA), enforced by the FCC, plus carrier guidelines from the CTIA. The cost of getting this wrong is real: penalties under the TCPA can reach roughly $500 to $1,500 per message, so compliance is not optional. The core requirements:

• Get prior express written consent before sending marketing texts. A purchased list or a phone number you happen to have is not consent.
• Disclose clearly at opt-in: who is texting, what kind of messages, message frequency, and that data rates may apply.
• Include an opt-out in your messages and honor "STOP" immediately, every time.
• Respect quiet hours: avoid texting outside reasonable local hours (generally before 8 a.m. or after 9 p.m. in the recipient's time zone).
• Register for A2P 10DLC. Beyond the law, U.S. carriers require business numbers to be registered, or messages get filtered and undelivered. For EU contacts, GDPR adds its own explicit-consent and data-rights obligations.

SMS marketing vs email marketing: which should you use?

This is the wrong question to ask as either/or, because the channels are complementary rather than competing. SMS wins on speed and attention; email wins on depth, design, and cost per message. The practical split most teams land on:

Use SMS for short, urgent, high-value moments: flash sales, restock alerts, shipping updates, VIP early access. Use email for the storytelling that needs room to breathe: newsletters, detailed product education, long promotions, and onboarding sequences. The strongest programs run both from one system so a subscriber's behavior in email can trigger a timely text, and vice versa. A modern CRM such as MapleConnect bundles SMS, email, and automation together so you don't have to stitch separate tools and consent records by hand.

How do I get started with SMS marketing?

You can launch a compliant program in a few focused steps. The order matters, especially registration, which trips up beginners who try to send before carriers approve their number:

1. Choose a platform that handles consent, opt-outs, and 10DLC registration for you.
2. Pick and register your sending number (10DLC, toll-free, or short code) and complete A2P brand and campaign registration.
3. Build your list with clear opt-in language at checkout, in pop-ups, or via a keyword, and capture proof of consent.
4. Start with transactional and welcome messages, which subscribers expect and appreciate, before layering in promotions.
5. Write tight copy: lead with the value, personalize where you can, add one clear call to action and a link, and include opt-out instructions.
6. Send at sensible times, then track delivery, clicks, conversions, and opt-outs to refine frequency and messaging.

SMS marketing best practices and common mistakes

The difference between a list that grows and one that collapses comes down to discipline. Keep these principles in view:

• Do get explicit consent and keep records; never text purchased or scraped numbers.
• Do identify your brand in the first message so the text isn't mistaken for spam.
• Do keep it short, valuable, and clearly actionable, and respect time zones.
• Don't over-send. Frequent, low-value blasts are the fastest way to spike opt-outs and trigger carrier filtering.
• Don't ignore replies. SMS is two-way; leaving questions unanswered erodes the trust that makes the channel work.
• Don't skip 10DLC registration or omit a STOP option, the two mistakes most likely to get your messages blocked or land you in legal trouble.